Verizon Hotspot/Tethering Issue on Samsung Galaxy S7

I do a lot of tethering on my android phone (currently Samsung Galaxy S7 with Verizon wireless).

Occasionally it will not let me turn on the mobile hotspot. Usually this is resolved by trying again, or re-starting the phone, or making sure I don't have a monthly data usage limit set that I might have exceeded (since I am not on an unlimited data plan).

This past week, nothing was working. It went over 24 hours without letting me turn on the hotspot. I kept getting the message:

          "checking subscription status" 

followed eventually by:

          "unable to connect at this time"

I looked online for solutions, but did not find anything relevant in the forums. I finally figured out that the hotspot started working again after I went to Settings / Connections / Data usage, and turned on "alert me about data usage". I don't understand why you should have to have this setting enabled to use the hotspot, but apparently you do.